1 // SPDX-License-Identifier: LGPL-2.1
2 #define _GNU_SOURCE
3 #include <assert.h>
4 #include <linux/membarrier.h>
5 #include <pthread.h>
6 #include <sched.h>
7 #include <stdatomic.h>
8 #include <stdint.h>
9 #include <stdio.h>
10 #include <stdlib.h>
11 #include <string.h>
12 #include <syscall.h>
13 #include <unistd.h>
14 #include <poll.h>
15 #include <sys/types.h>
16 #include <signal.h>
17 #include <errno.h>
18 #include <stddef.h>
19 
rseq_gettid(void)20 static inline pid_t rseq_gettid(void)
21 {
22 	return syscall(__NR_gettid);
23 }
24 
25 #define NR_INJECT	9
26 static int loop_cnt[NR_INJECT + 1];
27 
28 static int loop_cnt_1 asm("asm_loop_cnt_1") __attribute__((used));
29 static int loop_cnt_2 asm("asm_loop_cnt_2") __attribute__((used));
30 static int loop_cnt_3 asm("asm_loop_cnt_3") __attribute__((used));
31 static int loop_cnt_4 asm("asm_loop_cnt_4") __attribute__((used));
32 static int loop_cnt_5 asm("asm_loop_cnt_5") __attribute__((used));
33 static int loop_cnt_6 asm("asm_loop_cnt_6") __attribute__((used));
34 
35 static int opt_modulo, verbose;
36 
37 static int opt_yield, opt_signal, opt_sleep,
38 		opt_disable_rseq, opt_threads = 200,
39 		opt_disable_mod = 0, opt_test = 's', opt_mb = 0;
40 
41 #ifndef RSEQ_SKIP_FASTPATH
42 static long long opt_reps = 5000;
43 #else
44 static long long opt_reps = 100;
45 #endif
46 
47 static __thread __attribute__((tls_model("initial-exec")))
48 unsigned int signals_delivered;
49 
50 #ifndef BENCHMARK
51 
52 static __thread __attribute__((tls_model("initial-exec"), unused))
53 unsigned int yield_mod_cnt, nr_abort;
54 
55 #define printf_verbose(fmt, ...)			\
56 	do {						\
57 		if (verbose)				\
58 			printf(fmt, ## __VA_ARGS__);	\
59 	} while (0)
60 
61 #ifdef __i386__
62 
63 #define INJECT_ASM_REG	"eax"
64 
65 #define RSEQ_INJECT_CLOBBER \
66 	, INJECT_ASM_REG
67 
68 #define RSEQ_INJECT_ASM(n) \
69 	"mov asm_loop_cnt_" #n ", %%" INJECT_ASM_REG "\n\t" \
70 	"test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
71 	"jz 333f\n\t" \
72 	"222:\n\t" \
73 	"dec %%" INJECT_ASM_REG "\n\t" \
74 	"jnz 222b\n\t" \
75 	"333:\n\t"
76 
77 #elif defined(__x86_64__)
78 
79 #define INJECT_ASM_REG_P	"rax"
80 #define INJECT_ASM_REG		"eax"
81 
82 #define RSEQ_INJECT_CLOBBER \
83 	, INJECT_ASM_REG_P \
84 	, INJECT_ASM_REG
85 
86 #define RSEQ_INJECT_ASM(n) \
87 	"lea asm_loop_cnt_" #n "(%%rip), %%" INJECT_ASM_REG_P "\n\t" \
88 	"mov (%%" INJECT_ASM_REG_P "), %%" INJECT_ASM_REG "\n\t" \
89 	"test %%" INJECT_ASM_REG ",%%" INJECT_ASM_REG "\n\t" \
90 	"jz 333f\n\t" \
91 	"222:\n\t" \
92 	"dec %%" INJECT_ASM_REG "\n\t" \
93 	"jnz 222b\n\t" \
94 	"333:\n\t"
95 
96 #elif defined(__s390__)
97 
98 #define RSEQ_INJECT_INPUT \
99 	, [loop_cnt_1]"m"(loop_cnt[1]) \
100 	, [loop_cnt_2]"m"(loop_cnt[2]) \
101 	, [loop_cnt_3]"m"(loop_cnt[3]) \
102 	, [loop_cnt_4]"m"(loop_cnt[4]) \
103 	, [loop_cnt_5]"m"(loop_cnt[5]) \
104 	, [loop_cnt_6]"m"(loop_cnt[6])
105 
106 #define INJECT_ASM_REG	"r12"
107 
108 #define RSEQ_INJECT_CLOBBER \
109 	, INJECT_ASM_REG
110 
111 #define RSEQ_INJECT_ASM(n) \
112 	"l %%" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
113 	"ltr %%" INJECT_ASM_REG ", %%" INJECT_ASM_REG "\n\t" \
114 	"je 333f\n\t" \
115 	"222:\n\t" \
116 	"ahi %%" INJECT_ASM_REG ", -1\n\t" \
117 	"jnz 222b\n\t" \
118 	"333:\n\t"
119 
120 #elif defined(__ARMEL__)
121 
122 #define RSEQ_INJECT_INPUT \
123 	, [loop_cnt_1]"m"(loop_cnt[1]) \
124 	, [loop_cnt_2]"m"(loop_cnt[2]) \
125 	, [loop_cnt_3]"m"(loop_cnt[3]) \
126 	, [loop_cnt_4]"m"(loop_cnt[4]) \
127 	, [loop_cnt_5]"m"(loop_cnt[5]) \
128 	, [loop_cnt_6]"m"(loop_cnt[6])
129 
130 #define INJECT_ASM_REG	"r4"
131 
132 #define RSEQ_INJECT_CLOBBER \
133 	, INJECT_ASM_REG
134 
135 #define RSEQ_INJECT_ASM(n) \
136 	"ldr " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
137 	"cmp " INJECT_ASM_REG ", #0\n\t" \
138 	"beq 333f\n\t" \
139 	"222:\n\t" \
140 	"subs " INJECT_ASM_REG ", #1\n\t" \
141 	"bne 222b\n\t" \
142 	"333:\n\t"
143 
144 #elif defined(__AARCH64EL__)
145 
146 #define RSEQ_INJECT_INPUT \
147 	, [loop_cnt_1] "Qo" (loop_cnt[1]) \
148 	, [loop_cnt_2] "Qo" (loop_cnt[2]) \
149 	, [loop_cnt_3] "Qo" (loop_cnt[3]) \
150 	, [loop_cnt_4] "Qo" (loop_cnt[4]) \
151 	, [loop_cnt_5] "Qo" (loop_cnt[5]) \
152 	, [loop_cnt_6] "Qo" (loop_cnt[6])
153 
154 #define INJECT_ASM_REG	RSEQ_ASM_TMP_REG32
155 
156 #define RSEQ_INJECT_ASM(n) \
157 	"	ldr	" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n"	\
158 	"	cbz	" INJECT_ASM_REG ", 333f\n"			\
159 	"222:\n"							\
160 	"	sub	" INJECT_ASM_REG ", " INJECT_ASM_REG ", #1\n"	\
161 	"	cbnz	" INJECT_ASM_REG ", 222b\n"			\
162 	"333:\n"
163 
164 #elif __PPC__
165 
166 #define RSEQ_INJECT_INPUT \
167 	, [loop_cnt_1]"m"(loop_cnt[1]) \
168 	, [loop_cnt_2]"m"(loop_cnt[2]) \
169 	, [loop_cnt_3]"m"(loop_cnt[3]) \
170 	, [loop_cnt_4]"m"(loop_cnt[4]) \
171 	, [loop_cnt_5]"m"(loop_cnt[5]) \
172 	, [loop_cnt_6]"m"(loop_cnt[6])
173 
174 #define INJECT_ASM_REG	"r18"
175 
176 #define RSEQ_INJECT_CLOBBER \
177 	, INJECT_ASM_REG
178 
179 #define RSEQ_INJECT_ASM(n) \
180 	"lwz %%" INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
181 	"cmpwi %%" INJECT_ASM_REG ", 0\n\t" \
182 	"beq 333f\n\t" \
183 	"222:\n\t" \
184 	"subic. %%" INJECT_ASM_REG ", %%" INJECT_ASM_REG ", 1\n\t" \
185 	"bne 222b\n\t" \
186 	"333:\n\t"
187 
188 #elif defined(__mips__)
189 
190 #define RSEQ_INJECT_INPUT \
191 	, [loop_cnt_1]"m"(loop_cnt[1]) \
192 	, [loop_cnt_2]"m"(loop_cnt[2]) \
193 	, [loop_cnt_3]"m"(loop_cnt[3]) \
194 	, [loop_cnt_4]"m"(loop_cnt[4]) \
195 	, [loop_cnt_5]"m"(loop_cnt[5]) \
196 	, [loop_cnt_6]"m"(loop_cnt[6])
197 
198 #define INJECT_ASM_REG	"$5"
199 
200 #define RSEQ_INJECT_CLOBBER \
201 	, INJECT_ASM_REG
202 
203 #define RSEQ_INJECT_ASM(n) \
204 	"lw " INJECT_ASM_REG ", %[loop_cnt_" #n "]\n\t" \
205 	"beqz " INJECT_ASM_REG ", 333f\n\t" \
206 	"222:\n\t" \
207 	"addiu " INJECT_ASM_REG ", -1\n\t" \
208 	"bnez " INJECT_ASM_REG ", 222b\n\t" \
209 	"333:\n\t"
210 
211 #else
212 #error unsupported target
213 #endif
214 
215 #define RSEQ_INJECT_FAILED \
216 	nr_abort++;
217 
218 #define RSEQ_INJECT_C(n) \
219 { \
220 	int loc_i, loc_nr_loops = loop_cnt[n]; \
221 	\
222 	for (loc_i = 0; loc_i < loc_nr_loops; loc_i++) { \
223 		rseq_barrier(); \
224 	} \
225 	if (loc_nr_loops == -1 && opt_modulo) { \
226 		if (yield_mod_cnt == opt_modulo - 1) { \
227 			if (opt_sleep > 0) \
228 				poll(NULL, 0, opt_sleep); \
229 			if (opt_yield) \
230 				sched_yield(); \
231 			if (opt_signal) \
232 				raise(SIGUSR1); \
233 			yield_mod_cnt = 0; \
234 		} else { \
235 			yield_mod_cnt++; \
236 		} \
237 	} \
238 }
239 
240 #else
241 
242 #define printf_verbose(fmt, ...)
243 
244 #endif /* BENCHMARK */
245 
246 #include "rseq.h"
247 
248 struct percpu_lock_entry {
249 	intptr_t v;
250 } __attribute__((aligned(128)));
251 
252 struct percpu_lock {
253 	struct percpu_lock_entry c[CPU_SETSIZE];
254 };
255 
256 struct test_data_entry {
257 	intptr_t count;
258 } __attribute__((aligned(128)));
259 
260 struct spinlock_test_data {
261 	struct percpu_lock lock;
262 	struct test_data_entry c[CPU_SETSIZE];
263 };
264 
265 struct spinlock_thread_test_data {
266 	struct spinlock_test_data *data;
267 	long long reps;
268 	int reg;
269 };
270 
271 struct inc_test_data {
272 	struct test_data_entry c[CPU_SETSIZE];
273 };
274 
275 struct inc_thread_test_data {
276 	struct inc_test_data *data;
277 	long long reps;
278 	int reg;
279 };
280 
281 struct percpu_list_node {
282 	intptr_t data;
283 	struct percpu_list_node *next;
284 };
285 
286 struct percpu_list_entry {
287 	struct percpu_list_node *head;
288 } __attribute__((aligned(128)));
289 
290 struct percpu_list {
291 	struct percpu_list_entry c[CPU_SETSIZE];
292 };
293 
294 #define BUFFER_ITEM_PER_CPU	100
295 
296 struct percpu_buffer_node {
297 	intptr_t data;
298 };
299 
300 struct percpu_buffer_entry {
301 	intptr_t offset;
302 	intptr_t buflen;
303 	struct percpu_buffer_node **array;
304 } __attribute__((aligned(128)));
305 
306 struct percpu_buffer {
307 	struct percpu_buffer_entry c[CPU_SETSIZE];
308 };
309 
310 #define MEMCPY_BUFFER_ITEM_PER_CPU	100
311 
312 struct percpu_memcpy_buffer_node {
313 	intptr_t data1;
314 	uint64_t data2;
315 };
316 
317 struct percpu_memcpy_buffer_entry {
318 	intptr_t offset;
319 	intptr_t buflen;
320 	struct percpu_memcpy_buffer_node *array;
321 } __attribute__((aligned(128)));
322 
323 struct percpu_memcpy_buffer {
324 	struct percpu_memcpy_buffer_entry c[CPU_SETSIZE];
325 };
326 
327 /* A simple percpu spinlock. Grabs lock on current cpu. */
rseq_this_cpu_lock(struct percpu_lock * lock)328 static int rseq_this_cpu_lock(struct percpu_lock *lock)
329 {
330 	int cpu;
331 
332 	for (;;) {
333 		int ret;
334 
335 		cpu = rseq_cpu_start();
336 		ret = rseq_cmpeqv_storev(&lock->c[cpu].v,
337 					 0, 1, cpu);
338 		if (rseq_likely(!ret))
339 			break;
340 		/* Retry if comparison fails or rseq aborts. */
341 	}
342 	/*
343 	 * Acquire semantic when taking lock after control dependency.
344 	 * Matches rseq_smp_store_release().
345 	 */
346 	rseq_smp_acquire__after_ctrl_dep();
347 	return cpu;
348 }
349 
rseq_percpu_unlock(struct percpu_lock * lock,int cpu)350 static void rseq_percpu_unlock(struct percpu_lock *lock, int cpu)
351 {
352 	assert(lock->c[cpu].v == 1);
353 	/*
354 	 * Release lock, with release semantic. Matches
355 	 * rseq_smp_acquire__after_ctrl_dep().
356 	 */
357 	rseq_smp_store_release(&lock->c[cpu].v, 0);
358 }
359 
test_percpu_spinlock_thread(void * arg)360 void *test_percpu_spinlock_thread(void *arg)
361 {
362 	struct spinlock_thread_test_data *thread_data = arg;
363 	struct spinlock_test_data *data = thread_data->data;
364 	long long i, reps;
365 
366 	if (!opt_disable_rseq && thread_data->reg &&
367 	    rseq_register_current_thread())
368 		abort();
369 	reps = thread_data->reps;
370 	for (i = 0; i < reps; i++) {
371 		int cpu = rseq_cpu_start();
372 
373 		cpu = rseq_this_cpu_lock(&data->lock);
374 		data->c[cpu].count++;
375 		rseq_percpu_unlock(&data->lock, cpu);
376 #ifndef BENCHMARK
377 		if (i != 0 && !(i % (reps / 10)))
378 			printf_verbose("tid %d: count %lld\n",
379 				       (int) rseq_gettid(), i);
380 #endif
381 	}
382 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
383 		       (int) rseq_gettid(), nr_abort, signals_delivered);
384 	if (!opt_disable_rseq && thread_data->reg &&
385 	    rseq_unregister_current_thread())
386 		abort();
387 	return NULL;
388 }
389 
390 /*
391  * A simple test which implements a sharded counter using a per-cpu
392  * lock.  Obviously real applications might prefer to simply use a
393  * per-cpu increment; however, this is reasonable for a test and the
394  * lock can be extended to synchronize more complicated operations.
395  */
test_percpu_spinlock(void)396 void test_percpu_spinlock(void)
397 {
398 	const int num_threads = opt_threads;
399 	int i, ret;
400 	uint64_t sum;
401 	pthread_t test_threads[num_threads];
402 	struct spinlock_test_data data;
403 	struct spinlock_thread_test_data thread_data[num_threads];
404 
405 	memset(&data, 0, sizeof(data));
406 	for (i = 0; i < num_threads; i++) {
407 		thread_data[i].reps = opt_reps;
408 		if (opt_disable_mod <= 0 || (i % opt_disable_mod))
409 			thread_data[i].reg = 1;
410 		else
411 			thread_data[i].reg = 0;
412 		thread_data[i].data = &data;
413 		ret = pthread_create(&test_threads[i], NULL,
414 				     test_percpu_spinlock_thread,
415 				     &thread_data[i]);
416 		if (ret) {
417 			errno = ret;
418 			perror("pthread_create");
419 			abort();
420 		}
421 	}
422 
423 	for (i = 0; i < num_threads; i++) {
424 		ret = pthread_join(test_threads[i], NULL);
425 		if (ret) {
426 			errno = ret;
427 			perror("pthread_join");
428 			abort();
429 		}
430 	}
431 
432 	sum = 0;
433 	for (i = 0; i < CPU_SETSIZE; i++)
434 		sum += data.c[i].count;
435 
436 	assert(sum == (uint64_t)opt_reps * num_threads);
437 }
438 
test_percpu_inc_thread(void * arg)439 void *test_percpu_inc_thread(void *arg)
440 {
441 	struct inc_thread_test_data *thread_data = arg;
442 	struct inc_test_data *data = thread_data->data;
443 	long long i, reps;
444 
445 	if (!opt_disable_rseq && thread_data->reg &&
446 	    rseq_register_current_thread())
447 		abort();
448 	reps = thread_data->reps;
449 	for (i = 0; i < reps; i++) {
450 		int ret;
451 
452 		do {
453 			int cpu;
454 
455 			cpu = rseq_cpu_start();
456 			ret = rseq_addv(&data->c[cpu].count, 1, cpu);
457 		} while (rseq_unlikely(ret));
458 #ifndef BENCHMARK
459 		if (i != 0 && !(i % (reps / 10)))
460 			printf_verbose("tid %d: count %lld\n",
461 				       (int) rseq_gettid(), i);
462 #endif
463 	}
464 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
465 		       (int) rseq_gettid(), nr_abort, signals_delivered);
466 	if (!opt_disable_rseq && thread_data->reg &&
467 	    rseq_unregister_current_thread())
468 		abort();
469 	return NULL;
470 }
471 
test_percpu_inc(void)472 void test_percpu_inc(void)
473 {
474 	const int num_threads = opt_threads;
475 	int i, ret;
476 	uint64_t sum;
477 	pthread_t test_threads[num_threads];
478 	struct inc_test_data data;
479 	struct inc_thread_test_data thread_data[num_threads];
480 
481 	memset(&data, 0, sizeof(data));
482 	for (i = 0; i < num_threads; i++) {
483 		thread_data[i].reps = opt_reps;
484 		if (opt_disable_mod <= 0 || (i % opt_disable_mod))
485 			thread_data[i].reg = 1;
486 		else
487 			thread_data[i].reg = 0;
488 		thread_data[i].data = &data;
489 		ret = pthread_create(&test_threads[i], NULL,
490 				     test_percpu_inc_thread,
491 				     &thread_data[i]);
492 		if (ret) {
493 			errno = ret;
494 			perror("pthread_create");
495 			abort();
496 		}
497 	}
498 
499 	for (i = 0; i < num_threads; i++) {
500 		ret = pthread_join(test_threads[i], NULL);
501 		if (ret) {
502 			errno = ret;
503 			perror("pthread_join");
504 			abort();
505 		}
506 	}
507 
508 	sum = 0;
509 	for (i = 0; i < CPU_SETSIZE; i++)
510 		sum += data.c[i].count;
511 
512 	assert(sum == (uint64_t)opt_reps * num_threads);
513 }
514 
this_cpu_list_push(struct percpu_list * list,struct percpu_list_node * node,int * _cpu)515 void this_cpu_list_push(struct percpu_list *list,
516 			struct percpu_list_node *node,
517 			int *_cpu)
518 {
519 	int cpu;
520 
521 	for (;;) {
522 		intptr_t *targetptr, newval, expect;
523 		int ret;
524 
525 		cpu = rseq_cpu_start();
526 		/* Load list->c[cpu].head with single-copy atomicity. */
527 		expect = (intptr_t)RSEQ_READ_ONCE(list->c[cpu].head);
528 		newval = (intptr_t)node;
529 		targetptr = (intptr_t *)&list->c[cpu].head;
530 		node->next = (struct percpu_list_node *)expect;
531 		ret = rseq_cmpeqv_storev(targetptr, expect, newval, cpu);
532 		if (rseq_likely(!ret))
533 			break;
534 		/* Retry if comparison fails or rseq aborts. */
535 	}
536 	if (_cpu)
537 		*_cpu = cpu;
538 }
539 
540 /*
541  * Unlike a traditional lock-less linked list; the availability of a
542  * rseq primitive allows us to implement pop without concerns over
543  * ABA-type races.
544  */
this_cpu_list_pop(struct percpu_list * list,int * _cpu)545 struct percpu_list_node *this_cpu_list_pop(struct percpu_list *list,
546 					   int *_cpu)
547 {
548 	struct percpu_list_node *node = NULL;
549 	int cpu;
550 
551 	for (;;) {
552 		struct percpu_list_node *head;
553 		intptr_t *targetptr, expectnot, *load;
554 		off_t offset;
555 		int ret;
556 
557 		cpu = rseq_cpu_start();
558 		targetptr = (intptr_t *)&list->c[cpu].head;
559 		expectnot = (intptr_t)NULL;
560 		offset = offsetof(struct percpu_list_node, next);
561 		load = (intptr_t *)&head;
562 		ret = rseq_cmpnev_storeoffp_load(targetptr, expectnot,
563 						   offset, load, cpu);
564 		if (rseq_likely(!ret)) {
565 			node = head;
566 			break;
567 		}
568 		if (ret > 0)
569 			break;
570 		/* Retry if rseq aborts. */
571 	}
572 	if (_cpu)
573 		*_cpu = cpu;
574 	return node;
575 }
576 
577 /*
578  * __percpu_list_pop is not safe against concurrent accesses. Should
579  * only be used on lists that are not concurrently modified.
580  */
__percpu_list_pop(struct percpu_list * list,int cpu)581 struct percpu_list_node *__percpu_list_pop(struct percpu_list *list, int cpu)
582 {
583 	struct percpu_list_node *node;
584 
585 	node = list->c[cpu].head;
586 	if (!node)
587 		return NULL;
588 	list->c[cpu].head = node->next;
589 	return node;
590 }
591 
test_percpu_list_thread(void * arg)592 void *test_percpu_list_thread(void *arg)
593 {
594 	long long i, reps;
595 	struct percpu_list *list = (struct percpu_list *)arg;
596 
597 	if (!opt_disable_rseq && rseq_register_current_thread())
598 		abort();
599 
600 	reps = opt_reps;
601 	for (i = 0; i < reps; i++) {
602 		struct percpu_list_node *node;
603 
604 		node = this_cpu_list_pop(list, NULL);
605 		if (opt_yield)
606 			sched_yield();  /* encourage shuffling */
607 		if (node)
608 			this_cpu_list_push(list, node, NULL);
609 	}
610 
611 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
612 		       (int) rseq_gettid(), nr_abort, signals_delivered);
613 	if (!opt_disable_rseq && rseq_unregister_current_thread())
614 		abort();
615 
616 	return NULL;
617 }
618 
619 /* Simultaneous modification to a per-cpu linked list from many threads.  */
test_percpu_list(void)620 void test_percpu_list(void)
621 {
622 	const int num_threads = opt_threads;
623 	int i, j, ret;
624 	uint64_t sum = 0, expected_sum = 0;
625 	struct percpu_list list;
626 	pthread_t test_threads[num_threads];
627 	cpu_set_t allowed_cpus;
628 
629 	memset(&list, 0, sizeof(list));
630 
631 	/* Generate list entries for every usable cpu. */
632 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
633 	for (i = 0; i < CPU_SETSIZE; i++) {
634 		if (!CPU_ISSET(i, &allowed_cpus))
635 			continue;
636 		for (j = 1; j <= 100; j++) {
637 			struct percpu_list_node *node;
638 
639 			expected_sum += j;
640 
641 			node = malloc(sizeof(*node));
642 			assert(node);
643 			node->data = j;
644 			node->next = list.c[i].head;
645 			list.c[i].head = node;
646 		}
647 	}
648 
649 	for (i = 0; i < num_threads; i++) {
650 		ret = pthread_create(&test_threads[i], NULL,
651 				     test_percpu_list_thread, &list);
652 		if (ret) {
653 			errno = ret;
654 			perror("pthread_create");
655 			abort();
656 		}
657 	}
658 
659 	for (i = 0; i < num_threads; i++) {
660 		ret = pthread_join(test_threads[i], NULL);
661 		if (ret) {
662 			errno = ret;
663 			perror("pthread_join");
664 			abort();
665 		}
666 	}
667 
668 	for (i = 0; i < CPU_SETSIZE; i++) {
669 		struct percpu_list_node *node;
670 
671 		if (!CPU_ISSET(i, &allowed_cpus))
672 			continue;
673 
674 		while ((node = __percpu_list_pop(&list, i))) {
675 			sum += node->data;
676 			free(node);
677 		}
678 	}
679 
680 	/*
681 	 * All entries should now be accounted for (unless some external
682 	 * actor is interfering with our allowed affinity while this
683 	 * test is running).
684 	 */
685 	assert(sum == expected_sum);
686 }
687 
this_cpu_buffer_push(struct percpu_buffer * buffer,struct percpu_buffer_node * node,int * _cpu)688 bool this_cpu_buffer_push(struct percpu_buffer *buffer,
689 			  struct percpu_buffer_node *node,
690 			  int *_cpu)
691 {
692 	bool result = false;
693 	int cpu;
694 
695 	for (;;) {
696 		intptr_t *targetptr_spec, newval_spec;
697 		intptr_t *targetptr_final, newval_final;
698 		intptr_t offset;
699 		int ret;
700 
701 		cpu = rseq_cpu_start();
702 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
703 		if (offset == buffer->c[cpu].buflen)
704 			break;
705 		newval_spec = (intptr_t)node;
706 		targetptr_spec = (intptr_t *)&buffer->c[cpu].array[offset];
707 		newval_final = offset + 1;
708 		targetptr_final = &buffer->c[cpu].offset;
709 		if (opt_mb)
710 			ret = rseq_cmpeqv_trystorev_storev_release(
711 				targetptr_final, offset, targetptr_spec,
712 				newval_spec, newval_final, cpu);
713 		else
714 			ret = rseq_cmpeqv_trystorev_storev(targetptr_final,
715 				offset, targetptr_spec, newval_spec,
716 				newval_final, cpu);
717 		if (rseq_likely(!ret)) {
718 			result = true;
719 			break;
720 		}
721 		/* Retry if comparison fails or rseq aborts. */
722 	}
723 	if (_cpu)
724 		*_cpu = cpu;
725 	return result;
726 }
727 
this_cpu_buffer_pop(struct percpu_buffer * buffer,int * _cpu)728 struct percpu_buffer_node *this_cpu_buffer_pop(struct percpu_buffer *buffer,
729 					       int *_cpu)
730 {
731 	struct percpu_buffer_node *head;
732 	int cpu;
733 
734 	for (;;) {
735 		intptr_t *targetptr, newval;
736 		intptr_t offset;
737 		int ret;
738 
739 		cpu = rseq_cpu_start();
740 		/* Load offset with single-copy atomicity. */
741 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
742 		if (offset == 0) {
743 			head = NULL;
744 			break;
745 		}
746 		head = RSEQ_READ_ONCE(buffer->c[cpu].array[offset - 1]);
747 		newval = offset - 1;
748 		targetptr = (intptr_t *)&buffer->c[cpu].offset;
749 		ret = rseq_cmpeqv_cmpeqv_storev(targetptr, offset,
750 			(intptr_t *)&buffer->c[cpu].array[offset - 1],
751 			(intptr_t)head, newval, cpu);
752 		if (rseq_likely(!ret))
753 			break;
754 		/* Retry if comparison fails or rseq aborts. */
755 	}
756 	if (_cpu)
757 		*_cpu = cpu;
758 	return head;
759 }
760 
761 /*
762  * __percpu_buffer_pop is not safe against concurrent accesses. Should
763  * only be used on buffers that are not concurrently modified.
764  */
__percpu_buffer_pop(struct percpu_buffer * buffer,int cpu)765 struct percpu_buffer_node *__percpu_buffer_pop(struct percpu_buffer *buffer,
766 					       int cpu)
767 {
768 	struct percpu_buffer_node *head;
769 	intptr_t offset;
770 
771 	offset = buffer->c[cpu].offset;
772 	if (offset == 0)
773 		return NULL;
774 	head = buffer->c[cpu].array[offset - 1];
775 	buffer->c[cpu].offset = offset - 1;
776 	return head;
777 }
778 
test_percpu_buffer_thread(void * arg)779 void *test_percpu_buffer_thread(void *arg)
780 {
781 	long long i, reps;
782 	struct percpu_buffer *buffer = (struct percpu_buffer *)arg;
783 
784 	if (!opt_disable_rseq && rseq_register_current_thread())
785 		abort();
786 
787 	reps = opt_reps;
788 	for (i = 0; i < reps; i++) {
789 		struct percpu_buffer_node *node;
790 
791 		node = this_cpu_buffer_pop(buffer, NULL);
792 		if (opt_yield)
793 			sched_yield();  /* encourage shuffling */
794 		if (node) {
795 			if (!this_cpu_buffer_push(buffer, node, NULL)) {
796 				/* Should increase buffer size. */
797 				abort();
798 			}
799 		}
800 	}
801 
802 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
803 		       (int) rseq_gettid(), nr_abort, signals_delivered);
804 	if (!opt_disable_rseq && rseq_unregister_current_thread())
805 		abort();
806 
807 	return NULL;
808 }
809 
810 /* Simultaneous modification to a per-cpu buffer from many threads.  */
test_percpu_buffer(void)811 void test_percpu_buffer(void)
812 {
813 	const int num_threads = opt_threads;
814 	int i, j, ret;
815 	uint64_t sum = 0, expected_sum = 0;
816 	struct percpu_buffer buffer;
817 	pthread_t test_threads[num_threads];
818 	cpu_set_t allowed_cpus;
819 
820 	memset(&buffer, 0, sizeof(buffer));
821 
822 	/* Generate list entries for every usable cpu. */
823 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
824 	for (i = 0; i < CPU_SETSIZE; i++) {
825 		if (!CPU_ISSET(i, &allowed_cpus))
826 			continue;
827 		/* Worse-case is every item in same CPU. */
828 		buffer.c[i].array =
829 			malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
830 			       BUFFER_ITEM_PER_CPU);
831 		assert(buffer.c[i].array);
832 		buffer.c[i].buflen = CPU_SETSIZE * BUFFER_ITEM_PER_CPU;
833 		for (j = 1; j <= BUFFER_ITEM_PER_CPU; j++) {
834 			struct percpu_buffer_node *node;
835 
836 			expected_sum += j;
837 
838 			/*
839 			 * We could theoretically put the word-sized
840 			 * "data" directly in the buffer. However, we
841 			 * want to model objects that would not fit
842 			 * within a single word, so allocate an object
843 			 * for each node.
844 			 */
845 			node = malloc(sizeof(*node));
846 			assert(node);
847 			node->data = j;
848 			buffer.c[i].array[j - 1] = node;
849 			buffer.c[i].offset++;
850 		}
851 	}
852 
853 	for (i = 0; i < num_threads; i++) {
854 		ret = pthread_create(&test_threads[i], NULL,
855 				     test_percpu_buffer_thread, &buffer);
856 		if (ret) {
857 			errno = ret;
858 			perror("pthread_create");
859 			abort();
860 		}
861 	}
862 
863 	for (i = 0; i < num_threads; i++) {
864 		ret = pthread_join(test_threads[i], NULL);
865 		if (ret) {
866 			errno = ret;
867 			perror("pthread_join");
868 			abort();
869 		}
870 	}
871 
872 	for (i = 0; i < CPU_SETSIZE; i++) {
873 		struct percpu_buffer_node *node;
874 
875 		if (!CPU_ISSET(i, &allowed_cpus))
876 			continue;
877 
878 		while ((node = __percpu_buffer_pop(&buffer, i))) {
879 			sum += node->data;
880 			free(node);
881 		}
882 		free(buffer.c[i].array);
883 	}
884 
885 	/*
886 	 * All entries should now be accounted for (unless some external
887 	 * actor is interfering with our allowed affinity while this
888 	 * test is running).
889 	 */
890 	assert(sum == expected_sum);
891 }
892 
this_cpu_memcpy_buffer_push(struct percpu_memcpy_buffer * buffer,struct percpu_memcpy_buffer_node item,int * _cpu)893 bool this_cpu_memcpy_buffer_push(struct percpu_memcpy_buffer *buffer,
894 				 struct percpu_memcpy_buffer_node item,
895 				 int *_cpu)
896 {
897 	bool result = false;
898 	int cpu;
899 
900 	for (;;) {
901 		intptr_t *targetptr_final, newval_final, offset;
902 		char *destptr, *srcptr;
903 		size_t copylen;
904 		int ret;
905 
906 		cpu = rseq_cpu_start();
907 		/* Load offset with single-copy atomicity. */
908 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
909 		if (offset == buffer->c[cpu].buflen)
910 			break;
911 		destptr = (char *)&buffer->c[cpu].array[offset];
912 		srcptr = (char *)&item;
913 		/* copylen must be <= 4kB. */
914 		copylen = sizeof(item);
915 		newval_final = offset + 1;
916 		targetptr_final = &buffer->c[cpu].offset;
917 		if (opt_mb)
918 			ret = rseq_cmpeqv_trymemcpy_storev_release(
919 				targetptr_final, offset,
920 				destptr, srcptr, copylen,
921 				newval_final, cpu);
922 		else
923 			ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
924 				offset, destptr, srcptr, copylen,
925 				newval_final, cpu);
926 		if (rseq_likely(!ret)) {
927 			result = true;
928 			break;
929 		}
930 		/* Retry if comparison fails or rseq aborts. */
931 	}
932 	if (_cpu)
933 		*_cpu = cpu;
934 	return result;
935 }
936 
this_cpu_memcpy_buffer_pop(struct percpu_memcpy_buffer * buffer,struct percpu_memcpy_buffer_node * item,int * _cpu)937 bool this_cpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
938 				struct percpu_memcpy_buffer_node *item,
939 				int *_cpu)
940 {
941 	bool result = false;
942 	int cpu;
943 
944 	for (;;) {
945 		intptr_t *targetptr_final, newval_final, offset;
946 		char *destptr, *srcptr;
947 		size_t copylen;
948 		int ret;
949 
950 		cpu = rseq_cpu_start();
951 		/* Load offset with single-copy atomicity. */
952 		offset = RSEQ_READ_ONCE(buffer->c[cpu].offset);
953 		if (offset == 0)
954 			break;
955 		destptr = (char *)item;
956 		srcptr = (char *)&buffer->c[cpu].array[offset - 1];
957 		/* copylen must be <= 4kB. */
958 		copylen = sizeof(*item);
959 		newval_final = offset - 1;
960 		targetptr_final = &buffer->c[cpu].offset;
961 		ret = rseq_cmpeqv_trymemcpy_storev(targetptr_final,
962 			offset, destptr, srcptr, copylen,
963 			newval_final, cpu);
964 		if (rseq_likely(!ret)) {
965 			result = true;
966 			break;
967 		}
968 		/* Retry if comparison fails or rseq aborts. */
969 	}
970 	if (_cpu)
971 		*_cpu = cpu;
972 	return result;
973 }
974 
975 /*
976  * __percpu_memcpy_buffer_pop is not safe against concurrent accesses. Should
977  * only be used on buffers that are not concurrently modified.
978  */
__percpu_memcpy_buffer_pop(struct percpu_memcpy_buffer * buffer,struct percpu_memcpy_buffer_node * item,int cpu)979 bool __percpu_memcpy_buffer_pop(struct percpu_memcpy_buffer *buffer,
980 				struct percpu_memcpy_buffer_node *item,
981 				int cpu)
982 {
983 	intptr_t offset;
984 
985 	offset = buffer->c[cpu].offset;
986 	if (offset == 0)
987 		return false;
988 	memcpy(item, &buffer->c[cpu].array[offset - 1], sizeof(*item));
989 	buffer->c[cpu].offset = offset - 1;
990 	return true;
991 }
992 
test_percpu_memcpy_buffer_thread(void * arg)993 void *test_percpu_memcpy_buffer_thread(void *arg)
994 {
995 	long long i, reps;
996 	struct percpu_memcpy_buffer *buffer = (struct percpu_memcpy_buffer *)arg;
997 
998 	if (!opt_disable_rseq && rseq_register_current_thread())
999 		abort();
1000 
1001 	reps = opt_reps;
1002 	for (i = 0; i < reps; i++) {
1003 		struct percpu_memcpy_buffer_node item;
1004 		bool result;
1005 
1006 		result = this_cpu_memcpy_buffer_pop(buffer, &item, NULL);
1007 		if (opt_yield)
1008 			sched_yield();  /* encourage shuffling */
1009 		if (result) {
1010 			if (!this_cpu_memcpy_buffer_push(buffer, item, NULL)) {
1011 				/* Should increase buffer size. */
1012 				abort();
1013 			}
1014 		}
1015 	}
1016 
1017 	printf_verbose("tid %d: number of rseq abort: %d, signals delivered: %u\n",
1018 		       (int) rseq_gettid(), nr_abort, signals_delivered);
1019 	if (!opt_disable_rseq && rseq_unregister_current_thread())
1020 		abort();
1021 
1022 	return NULL;
1023 }
1024 
1025 /* Simultaneous modification to a per-cpu buffer from many threads.  */
test_percpu_memcpy_buffer(void)1026 void test_percpu_memcpy_buffer(void)
1027 {
1028 	const int num_threads = opt_threads;
1029 	int i, j, ret;
1030 	uint64_t sum = 0, expected_sum = 0;
1031 	struct percpu_memcpy_buffer buffer;
1032 	pthread_t test_threads[num_threads];
1033 	cpu_set_t allowed_cpus;
1034 
1035 	memset(&buffer, 0, sizeof(buffer));
1036 
1037 	/* Generate list entries for every usable cpu. */
1038 	sched_getaffinity(0, sizeof(allowed_cpus), &allowed_cpus);
1039 	for (i = 0; i < CPU_SETSIZE; i++) {
1040 		if (!CPU_ISSET(i, &allowed_cpus))
1041 			continue;
1042 		/* Worse-case is every item in same CPU. */
1043 		buffer.c[i].array =
1044 			malloc(sizeof(*buffer.c[i].array) * CPU_SETSIZE *
1045 			       MEMCPY_BUFFER_ITEM_PER_CPU);
1046 		assert(buffer.c[i].array);
1047 		buffer.c[i].buflen = CPU_SETSIZE * MEMCPY_BUFFER_ITEM_PER_CPU;
1048 		for (j = 1; j <= MEMCPY_BUFFER_ITEM_PER_CPU; j++) {
1049 			expected_sum += 2 * j + 1;
1050 
1051 			/*
1052 			 * We could theoretically put the word-sized
1053 			 * "data" directly in the buffer. However, we
1054 			 * want to model objects that would not fit
1055 			 * within a single word, so allocate an object
1056 			 * for each node.
1057 			 */
1058 			buffer.c[i].array[j - 1].data1 = j;
1059 			buffer.c[i].array[j - 1].data2 = j + 1;
1060 			buffer.c[i].offset++;
1061 		}
1062 	}
1063 
1064 	for (i = 0; i < num_threads; i++) {
1065 		ret = pthread_create(&test_threads[i], NULL,
1066 				     test_percpu_memcpy_buffer_thread,
1067 				     &buffer);
1068 		if (ret) {
1069 			errno = ret;
1070 			perror("pthread_create");
1071 			abort();
1072 		}
1073 	}
1074 
1075 	for (i = 0; i < num_threads; i++) {
1076 		ret = pthread_join(test_threads[i], NULL);
1077 		if (ret) {
1078 			errno = ret;
1079 			perror("pthread_join");
1080 			abort();
1081 		}
1082 	}
1083 
1084 	for (i = 0; i < CPU_SETSIZE; i++) {
1085 		struct percpu_memcpy_buffer_node item;
1086 
1087 		if (!CPU_ISSET(i, &allowed_cpus))
1088 			continue;
1089 
1090 		while (__percpu_memcpy_buffer_pop(&buffer, &item, i)) {
1091 			sum += item.data1;
1092 			sum += item.data2;
1093 		}
1094 		free(buffer.c[i].array);
1095 	}
1096 
1097 	/*
1098 	 * All entries should now be accounted for (unless some external
1099 	 * actor is interfering with our allowed affinity while this
1100 	 * test is running).
1101 	 */
1102 	assert(sum == expected_sum);
1103 }
1104 
test_signal_interrupt_handler(int signo)1105 static void test_signal_interrupt_handler(int signo)
1106 {
1107 	signals_delivered++;
1108 }
1109 
set_signal_handler(void)1110 static int set_signal_handler(void)
1111 {
1112 	int ret = 0;
1113 	struct sigaction sa;
1114 	sigset_t sigset;
1115 
1116 	ret = sigemptyset(&sigset);
1117 	if (ret < 0) {
1118 		perror("sigemptyset");
1119 		return ret;
1120 	}
1121 
1122 	sa.sa_handler = test_signal_interrupt_handler;
1123 	sa.sa_mask = sigset;
1124 	sa.sa_flags = 0;
1125 	ret = sigaction(SIGUSR1, &sa, NULL);
1126 	if (ret < 0) {
1127 		perror("sigaction");
1128 		return ret;
1129 	}
1130 
1131 	printf_verbose("Signal handler set for SIGUSR1\n");
1132 
1133 	return ret;
1134 }
1135 
1136 /* Test MEMBARRIER_CMD_PRIVATE_RESTART_RSEQ_ON_CPU membarrier command. */
1137 #ifdef RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV
1138 struct test_membarrier_thread_args {
1139 	int stop;
1140 	intptr_t percpu_list_ptr;
1141 };
1142 
1143 /* Worker threads modify data in their "active" percpu lists. */
test_membarrier_worker_thread(void * arg)1144 void *test_membarrier_worker_thread(void *arg)
1145 {
1146 	struct test_membarrier_thread_args *args =
1147 		(struct test_membarrier_thread_args *)arg;
1148 	const int iters = opt_reps;
1149 	int i;
1150 
1151 	if (rseq_register_current_thread()) {
1152 		fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
1153 			errno, strerror(errno));
1154 		abort();
1155 	}
1156 
1157 	/* Wait for initialization. */
1158 	while (!atomic_load(&args->percpu_list_ptr)) {}
1159 
1160 	for (i = 0; i < iters; ++i) {
1161 		int ret;
1162 
1163 		do {
1164 			int cpu = rseq_cpu_start();
1165 
1166 			ret = rseq_offset_deref_addv(&args->percpu_list_ptr,
1167 				sizeof(struct percpu_list_entry) * cpu, 1, cpu);
1168 		} while (rseq_unlikely(ret));
1169 	}
1170 
1171 	if (rseq_unregister_current_thread()) {
1172 		fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
1173 			errno, strerror(errno));
1174 		abort();
1175 	}
1176 	return NULL;
1177 }
1178 
test_membarrier_init_percpu_list(struct percpu_list * list)1179 void test_membarrier_init_percpu_list(struct percpu_list *list)
1180 {
1181 	int i;
1182 
1183 	memset(list, 0, sizeof(*list));
1184 	for (i = 0; i < CPU_SETSIZE; i++) {
1185 		struct percpu_list_node *node;
1186 
1187 		node = malloc(sizeof(*node));
1188 		assert(node);
1189 		node->data = 0;
1190 		node->next = NULL;
1191 		list->c[i].head = node;
1192 	}
1193 }
1194 
test_membarrier_free_percpu_list(struct percpu_list * list)1195 void test_membarrier_free_percpu_list(struct percpu_list *list)
1196 {
1197 	int i;
1198 
1199 	for (i = 0; i < CPU_SETSIZE; i++)
1200 		free(list->c[i].head);
1201 }
1202 
sys_membarrier(int cmd,int flags,int cpu_id)1203 static int sys_membarrier(int cmd, int flags, int cpu_id)
1204 {
1205 	return syscall(__NR_membarrier, cmd, flags, cpu_id);
1206 }
1207 
1208 /*
1209  * The manager thread swaps per-cpu lists that worker threads see,
1210  * and validates that there are no unexpected modifications.
1211  */
test_membarrier_manager_thread(void * arg)1212 void *test_membarrier_manager_thread(void *arg)
1213 {
1214 	struct test_membarrier_thread_args *args =
1215 		(struct test_membarrier_thread_args *)arg;
1216 	struct percpu_list list_a, list_b;
1217 	intptr_t expect_a = 0, expect_b = 0;
1218 	int cpu_a = 0, cpu_b = 0;
1219 
1220 	if (rseq_register_current_thread()) {
1221 		fprintf(stderr, "Error: rseq_register_current_thread(...) failed(%d): %s\n",
1222 			errno, strerror(errno));
1223 		abort();
1224 	}
1225 
1226 	/* Init lists. */
1227 	test_membarrier_init_percpu_list(&list_a);
1228 	test_membarrier_init_percpu_list(&list_b);
1229 
1230 	atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a);
1231 
1232 	while (!atomic_load(&args->stop)) {
1233 		/* list_a is "active". */
1234 		cpu_a = rand() % CPU_SETSIZE;
1235 		/*
1236 		 * As list_b is "inactive", we should never see changes
1237 		 * to list_b.
1238 		 */
1239 		if (expect_b != atomic_load(&list_b.c[cpu_b].head->data)) {
1240 			fprintf(stderr, "Membarrier test failed\n");
1241 			abort();
1242 		}
1243 
1244 		/* Make list_b "active". */
1245 		atomic_store(&args->percpu_list_ptr, (intptr_t)&list_b);
1246 		if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
1247 					MEMBARRIER_CMD_FLAG_CPU, cpu_a) &&
1248 				errno != ENXIO /* missing CPU */) {
1249 			perror("sys_membarrier");
1250 			abort();
1251 		}
1252 		/*
1253 		 * Cpu A should now only modify list_b, so the values
1254 		 * in list_a should be stable.
1255 		 */
1256 		expect_a = atomic_load(&list_a.c[cpu_a].head->data);
1257 
1258 		cpu_b = rand() % CPU_SETSIZE;
1259 		/*
1260 		 * As list_a is "inactive", we should never see changes
1261 		 * to list_a.
1262 		 */
1263 		if (expect_a != atomic_load(&list_a.c[cpu_a].head->data)) {
1264 			fprintf(stderr, "Membarrier test failed\n");
1265 			abort();
1266 		}
1267 
1268 		/* Make list_a "active". */
1269 		atomic_store(&args->percpu_list_ptr, (intptr_t)&list_a);
1270 		if (sys_membarrier(MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ,
1271 					MEMBARRIER_CMD_FLAG_CPU, cpu_b) &&
1272 				errno != ENXIO /* missing CPU*/) {
1273 			perror("sys_membarrier");
1274 			abort();
1275 		}
1276 		/* Remember a value from list_b. */
1277 		expect_b = atomic_load(&list_b.c[cpu_b].head->data);
1278 	}
1279 
1280 	test_membarrier_free_percpu_list(&list_a);
1281 	test_membarrier_free_percpu_list(&list_b);
1282 
1283 	if (rseq_unregister_current_thread()) {
1284 		fprintf(stderr, "Error: rseq_unregister_current_thread(...) failed(%d): %s\n",
1285 			errno, strerror(errno));
1286 		abort();
1287 	}
1288 	return NULL;
1289 }
1290 
test_membarrier(void)1291 void test_membarrier(void)
1292 {
1293 	const int num_threads = opt_threads;
1294 	struct test_membarrier_thread_args thread_args;
1295 	pthread_t worker_threads[num_threads];
1296 	pthread_t manager_thread;
1297 	int i, ret;
1298 
1299 	if (sys_membarrier(MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_RSEQ, 0, 0)) {
1300 		perror("sys_membarrier");
1301 		abort();
1302 	}
1303 
1304 	thread_args.stop = 0;
1305 	thread_args.percpu_list_ptr = 0;
1306 	ret = pthread_create(&manager_thread, NULL,
1307 			test_membarrier_manager_thread, &thread_args);
1308 	if (ret) {
1309 		errno = ret;
1310 		perror("pthread_create");
1311 		abort();
1312 	}
1313 
1314 	for (i = 0; i < num_threads; i++) {
1315 		ret = pthread_create(&worker_threads[i], NULL,
1316 				test_membarrier_worker_thread, &thread_args);
1317 		if (ret) {
1318 			errno = ret;
1319 			perror("pthread_create");
1320 			abort();
1321 		}
1322 	}
1323 
1324 
1325 	for (i = 0; i < num_threads; i++) {
1326 		ret = pthread_join(worker_threads[i], NULL);
1327 		if (ret) {
1328 			errno = ret;
1329 			perror("pthread_join");
1330 			abort();
1331 		}
1332 	}
1333 
1334 	atomic_store(&thread_args.stop, 1);
1335 	ret = pthread_join(manager_thread, NULL);
1336 	if (ret) {
1337 		errno = ret;
1338 		perror("pthread_join");
1339 		abort();
1340 	}
1341 }
1342 #else /* RSEQ_ARCH_HAS_OFFSET_DEREF_ADDV */
test_membarrier(void)1343 void test_membarrier(void)
1344 {
1345 	fprintf(stderr, "rseq_offset_deref_addv is not implemented on this architecture. "
1346 			"Skipping membarrier test.\n");
1347 }
1348 #endif
1349 
show_usage(int argc,char ** argv)1350 static void show_usage(int argc, char **argv)
1351 {
1352 	printf("Usage : %s <OPTIONS>\n",
1353 		argv[0]);
1354 	printf("OPTIONS:\n");
1355 	printf("	[-1 loops] Number of loops for delay injection 1\n");
1356 	printf("	[-2 loops] Number of loops for delay injection 2\n");
1357 	printf("	[-3 loops] Number of loops for delay injection 3\n");
1358 	printf("	[-4 loops] Number of loops for delay injection 4\n");
1359 	printf("	[-5 loops] Number of loops for delay injection 5\n");
1360 	printf("	[-6 loops] Number of loops for delay injection 6\n");
1361 	printf("	[-7 loops] Number of loops for delay injection 7 (-1 to enable -m)\n");
1362 	printf("	[-8 loops] Number of loops for delay injection 8 (-1 to enable -m)\n");
1363 	printf("	[-9 loops] Number of loops for delay injection 9 (-1 to enable -m)\n");
1364 	printf("	[-m N] Yield/sleep/kill every modulo N (default 0: disabled) (>= 0)\n");
1365 	printf("	[-y] Yield\n");
1366 	printf("	[-k] Kill thread with signal\n");
1367 	printf("	[-s S] S: =0: disabled (default), >0: sleep time (ms)\n");
1368 	printf("	[-t N] Number of threads (default 200)\n");
1369 	printf("	[-r N] Number of repetitions per thread (default 5000)\n");
1370 	printf("	[-d] Disable rseq system call (no initialization)\n");
1371 	printf("	[-D M] Disable rseq for each M threads\n");
1372 	printf("	[-T test] Choose test: (s)pinlock, (l)ist, (b)uffer, (m)emcpy, (i)ncrement, membarrie(r)\n");
1373 	printf("	[-M] Push into buffer and memcpy buffer with memory barriers.\n");
1374 	printf("	[-v] Verbose output.\n");
1375 	printf("	[-h] Show this help.\n");
1376 	printf("\n");
1377 }
1378 
main(int argc,char ** argv)1379 int main(int argc, char **argv)
1380 {
1381 	int i;
1382 
1383 	for (i = 1; i < argc; i++) {
1384 		if (argv[i][0] != '-')
1385 			continue;
1386 		switch (argv[i][1]) {
1387 		case '1':
1388 		case '2':
1389 		case '3':
1390 		case '4':
1391 		case '5':
1392 		case '6':
1393 		case '7':
1394 		case '8':
1395 		case '9':
1396 			if (argc < i + 2) {
1397 				show_usage(argc, argv);
1398 				goto error;
1399 			}
1400 			loop_cnt[argv[i][1] - '0'] = atol(argv[i + 1]);
1401 			i++;
1402 			break;
1403 		case 'm':
1404 			if (argc < i + 2) {
1405 				show_usage(argc, argv);
1406 				goto error;
1407 			}
1408 			opt_modulo = atol(argv[i + 1]);
1409 			if (opt_modulo < 0) {
1410 				show_usage(argc, argv);
1411 				goto error;
1412 			}
1413 			i++;
1414 			break;
1415 		case 's':
1416 			if (argc < i + 2) {
1417 				show_usage(argc, argv);
1418 				goto error;
1419 			}
1420 			opt_sleep = atol(argv[i + 1]);
1421 			if (opt_sleep < 0) {
1422 				show_usage(argc, argv);
1423 				goto error;
1424 			}
1425 			i++;
1426 			break;
1427 		case 'y':
1428 			opt_yield = 1;
1429 			break;
1430 		case 'k':
1431 			opt_signal = 1;
1432 			break;
1433 		case 'd':
1434 			opt_disable_rseq = 1;
1435 			break;
1436 		case 'D':
1437 			if (argc < i + 2) {
1438 				show_usage(argc, argv);
1439 				goto error;
1440 			}
1441 			opt_disable_mod = atol(argv[i + 1]);
1442 			if (opt_disable_mod < 0) {
1443 				show_usage(argc, argv);
1444 				goto error;
1445 			}
1446 			i++;
1447 			break;
1448 		case 't':
1449 			if (argc < i + 2) {
1450 				show_usage(argc, argv);
1451 				goto error;
1452 			}
1453 			opt_threads = atol(argv[i + 1]);
1454 			if (opt_threads < 0) {
1455 				show_usage(argc, argv);
1456 				goto error;
1457 			}
1458 			i++;
1459 			break;
1460 		case 'r':
1461 			if (argc < i + 2) {
1462 				show_usage(argc, argv);
1463 				goto error;
1464 			}
1465 			opt_reps = atoll(argv[i + 1]);
1466 			if (opt_reps < 0) {
1467 				show_usage(argc, argv);
1468 				goto error;
1469 			}
1470 			i++;
1471 			break;
1472 		case 'h':
1473 			show_usage(argc, argv);
1474 			goto end;
1475 		case 'T':
1476 			if (argc < i + 2) {
1477 				show_usage(argc, argv);
1478 				goto error;
1479 			}
1480 			opt_test = *argv[i + 1];
1481 			switch (opt_test) {
1482 			case 's':
1483 			case 'l':
1484 			case 'i':
1485 			case 'b':
1486 			case 'm':
1487 			case 'r':
1488 				break;
1489 			default:
1490 				show_usage(argc, argv);
1491 				goto error;
1492 			}
1493 			i++;
1494 			break;
1495 		case 'v':
1496 			verbose = 1;
1497 			break;
1498 		case 'M':
1499 			opt_mb = 1;
1500 			break;
1501 		default:
1502 			show_usage(argc, argv);
1503 			goto error;
1504 		}
1505 	}
1506 
1507 	loop_cnt_1 = loop_cnt[1];
1508 	loop_cnt_2 = loop_cnt[2];
1509 	loop_cnt_3 = loop_cnt[3];
1510 	loop_cnt_4 = loop_cnt[4];
1511 	loop_cnt_5 = loop_cnt[5];
1512 	loop_cnt_6 = loop_cnt[6];
1513 
1514 	if (set_signal_handler())
1515 		goto error;
1516 
1517 	if (!opt_disable_rseq && rseq_register_current_thread())
1518 		goto error;
1519 	switch (opt_test) {
1520 	case 's':
1521 		printf_verbose("spinlock\n");
1522 		test_percpu_spinlock();
1523 		break;
1524 	case 'l':
1525 		printf_verbose("linked list\n");
1526 		test_percpu_list();
1527 		break;
1528 	case 'b':
1529 		printf_verbose("buffer\n");
1530 		test_percpu_buffer();
1531 		break;
1532 	case 'm':
1533 		printf_verbose("memcpy buffer\n");
1534 		test_percpu_memcpy_buffer();
1535 		break;
1536 	case 'i':
1537 		printf_verbose("counter increment\n");
1538 		test_percpu_inc();
1539 		break;
1540 	case 'r':
1541 		printf_verbose("membarrier\n");
1542 		test_membarrier();
1543 		break;
1544 	}
1545 	if (!opt_disable_rseq && rseq_unregister_current_thread())
1546 		abort();
1547 end:
1548 	return 0;
1549 
1550 error:
1551 	return -1;
1552 }
1553